The use of optical and/or optoelectronic devices is increasing in communications applications. During the operation of these devices it is often desirable to monitor the light traveling along a waveguide at a mid-point on the waveguide rather than at the end of the waveguide. A tap waveguide is often used for this purpose. A tap waveguide intersects a main waveguide that is carrying the light signal to be monitored. The tap waveguide extracts a small portion of that light signal from the main waveguide and then carries the extracted portion of the light signal to a light sensor positioned at an end of the tap waveguide. The output of the light sensor is then used to monitor the light signal on the main waveguide.
The presence of these tap waveguides can increase the size and/or complexity of optical and/or optoelectronic devices. However, it is desirable for the optical and/or optoelectronic devices used in communications devices to be reduced or minimized. As a result, there is a need for improved techniques for monitoring light signals traveling along a waveguide at a mid-point on the waveguide.